The present invention relates to a pressure regulator for controlling a pre-injection quantity of fuel in internal combustion engines, preferably Diesel engines.
For a reliable and clean mixture formation within the combustion chamber, today's internal combustion engines, Diesel engines in particular, require an injection process consisting of several individual injection actions. These injection processes are divided into pre-injection and main injection of the fuel quantity. For producing the pre-injection fuel quantity, a control unit is employed which requires a high-cost electronic control system and which shows energetic losses. Frequently, a damper is employed for producing the pre-injection fuel quantity. This damper, however, cannot be fully utilized in each step of the operation. The reason for this is that the response time of the control hydraulic is too long in the event of small injection quantities due to the design of the control elements and a small pre-injection quantity can, therefore, be produced only with the help of a significant control-technical structural design and expenditure.
Therefore, it is an object of the present invention to provide the pressure regulator of the aforementioned kind such that a pre-injection quantity of fuel can be produced in each step of the operation without the necessity of a high control-technical structural design and expenditure.